Cardiac arrhythmias during epinephrine-propranolol infusions for measurement of in vivo insulin resistance.

Sixty-eight determination of in vivo insulin resistance were conducted in 35 males (aged 29-63 yr) by measurement of steady-state plasma glucose levels during a combined intravenous infusion of propranolol, epinephrine, glucose, and insulin. Subjects were mildly diabetic and/or hyperlipidemic. All were asymptomatic, denied taking medication, and had no history of cardiac disease. All had normal resting electrocardiograms. During the infusion, mean increases in systolic and diastolic blood pressure were 27 +/- 12.2 (x +/- SD) and 14 +/- 5.7 mm Hg, respectively; mean reduction in heart rate was 19 +/- 6.1 beats/min. Six out of the 35 subjects developed cardiac arrhythmias during the infusion test. Maximal exercise treadmill tests failed to predict all subjects who subsequently developed arrhythmias during the infusion test. These results suggest that this infusion test should be performed under continuous cardiac monitoring and promptly terminated if major arrhythmias develop.

Effects of a physical activity program on metabolic control and cardiovascular fitness in children with insulin-dependent diabetes mellitus.

The purpose of this investigation was to determine the effects of a regular vigorous physical activity program on children aged 5-11 yr with insulin-dependent diabetes mellitus (IDDM). The experimental group of children (N = 9) took part in a 30-min vigorous exercise program three times a week for 12 wk; the control group (N = 10) did not. Hemoglobin A1 (HbA1) and fasting blood glucose (FBG) were used to determine metabolic control. Oxygen consumption was evaluated by treadmill testing and analyses of expired air. The experimental group significantly (P less than 0.05) decreased their HbA1 and FBG while the control group showed no change. The experimental group significantly (P less than 0.05) increased their peak aerobic capacity (ml/kg . min) when compared with baseline values (47.14 +/- 1.94 versus 50.69 +/- 1.30). It was concluded that a carefully applied program of regular vigorous physical activity can beneficially influence metabolic control and cardiovascular fitness in young children with IDDM.

Risk factors for postoperative wound infections and prolonged hospitalization after ventral/incisional hernia repair.

PURPOSE: The purpose of this study was to identify predictive factors for postoperative surgical site infections (SSIs), and increased length of hospital stay (LOS) after ventral/incisional hernia repair (VIHR) using multi-center, prospectively collected data. STUDY DESIGN: Cases of VIHR from 2009 to 2010 were identified in the American College of Surgeons National Surgical Quality Improvement Program database. Using logistic regression, a prediction model utilizing 41 variables was developed to identify risk factors for postoperative SSIs, and increased LOS. Separate analyses were carried out for reducible and incarcerated/strangulated cases. RESULTS: A total of 28,269 cases of VIHR were identified, 25,172 of which met inclusion criteria. 18,263 cases were reducible hernias, and 6,909 cases were incarcerated/strangulated hernias. Our prediction model demonstrated that body mass index ≥30 kg/m(2), smoking, American Society of Anesthesiology (ASA) class 3, open surgical approach, prolonged operative times, and inpatient admission following VIHR were significant predictors of postoperative SSIs. In addition, risk factors associated with prolonged LOS included older age, African American ethnicity, history of alcohol abuse, ASA classes 3 and 4, poor functional status, operation within the last 30 days of the index operation, history of chronic obstructive pulmonary disease, congestive heart failure, and bleeding disorder, as well as open surgical approach, non-involvement of residents, prolonged operative times, recurrent hernia, emergency operation, and low preoperative serum albumin level. CONCLUSIONS: Obesity and smoking are modifiable risk factors for SSIs after VIHR, whereas a low serum albumin level is a modifiable risk factor for prolonged LOS. Addressing factors preoperatively might improve patient outcome, and reduce health care expenditures associated with VIHR. In addition, if feasible, the laparoscopic approach should be strongly considered.

The effect of adrenergic receptor blockade on the exercise-induced rise in pancreatic polypeptide in man.

The effect of adrenergic receptor-blocking agents upon plasma levels of human pancreatic polypeptide (hPP), human GH (hGH), immunoreactive insulin, and glucose during graded submaximal exercise was ascertained in six healthy nonobese males. Subjects exercised from 0--27 min on a motor-driven treadmill and received infusions from -10 to 40 min of either 1) saline, 2) saline plus phentolamine (0.5 mg/min; alpha-adrenergic blockade), or 3) propranolol (3 mg) from -10 to -5 min, followed by saline plus propranolol (0.08 mg/min; beta-adrenergic blockade). During saline-exercise, mean plasma hPP rose from a mean (+/-SE) basal level of 45 +/- 11 to 149 +/- 51 pg/ml at 27 min, whereas with phentolamine-exercise, the maximal level reached by mean plasma hPP (305 +/- 28 pg/ml) was significantly greater than that with saline (P less than 0.05). During propranolol-exercise, mean plasma hPP did not rise significantly above the basal level. The incremental area under the hPP curve for phentolamine-exercise also was significantly greater than that for saline-exercise or propranolol-exercise. The changes in plasma hGH during and after saline-exercise correlated with those of hPP, but the effects of phentolamine and propranolol upon exercise-induced increases in hGH were opposite to the effects upon hPP. The exercise-induced fall in immunoreactive insulin was accentuated with propranolol and abolished with phentolamine. It is concluded that 1) submaximal exercise stimulates secretion of hPP and hGH, 2) adrnergic mechanisms participate in exercise-induced increased secretion of hPP (beta-adrenergic stimulation augments secretion and alpha-adrenergic stimulation inhibits secretion), and 3) adrenergic effects which modulate exercise-induced secretion of hPP and insulin are in parallel but are opposite to those that modulate the secretion of hGH.

Type IV hyperlipoproteinemia: effects of a caloric restricted type IV diet versus physical training plus isocaloric type IV diet.

Serum lipids, plasma insulin and glucagon, aerobic capacity, and body composition were examined in middle-aged men (X age = 44.2 years) with type IV hyperlipoproteinemia to determine the relative effectiveness of a caloric restricted type IV hyperlipoproteinemia diet (group A) versus physical training plus an isocaloric type IV diet (group B). After 9 weeks of the above interventions, reductions (P less than 0.01) in mean cholesterol levels from 213 to 186 (12% change) and from 205 to 185 mg/dl (9% change), and in triglyceride levels from 332 to 211 (29% change) and from 263 to 138 mg/dl (42% change) were found for groups A and B, respectively. A small reduction in mean fasting insulin level was found only in group B; this reduction appeared inversely associated with increases in aerobic capacity in group B (r = -0.66). Both interventions were without effect on fasting glucagon levels. The physical training program prescribed resulted in a 12% increase in aerobic capacity (group B). Significant mean body weight reductions of 7.7 lb (P less than 0.01) and 2.9 lb (P less than 0.01) were seen for groups A and B, respectively; these absolute body weight reductions differed significantly (P less than 0.05) between groups. Both groups significantly lost body fatness (P less than 0.01). These reductions in body weight and body fatness appeared independent of changes in lipid levels. These results demonstrate that both interventions reduce serum lipids in men with type IV hyperlipoproteinemia but that physical training plus an isocaloric type IV diet may be the more advantageous of the two regimens, since a greater percentage decrease and a more sustained reduction in serum triglyceride levels, and a greater reduction of fasting hyperinsulinemia were observed in group B.

Noninvasive evaluation of hand circulation before radial artery harvest for coronary artery bypass grafting.

OBJECTIVE: Radial artery harvesting for coronary artery bypass may lead to digit ischemia if collateral hand circulation is inadequate. The modified Allen's test is the most common preoperative screening test used. Unfortunately, this test has high false-positive and false-negative rates. The purpose of this study was to compare the results of a modified Allen's test with digit pressure change during radial artery compression for assessing collateral circulation before radial artery harvest. METHODS: One hundred twenty-nine consecutive patients were studied before coronary artery bypass operations. A modified Allen's test was performed with Doppler ultrasound to assess blood flow in the superficial palmar arch before and during radial artery compression. A decreased audible Doppler signal after radial artery compression was considered a positive modified Allen's test. First and second digit pressures were measured before and during radial artery compression. A decrease in digit pressure of 40 mm Hg or more (digit DeltaP) with radial artery compression was considered positive. RESULTS: Seven of 14 dominant extremities (50%) and 8 of the 16 nondominant extremities (50%) with a positive modified Allen's test had a digit DeltaP of less than 40 mm Hg (false positive). Sixteen of 115 dominant extremities (14%) and 5 of 112 nondominant extremities (4%) with a negative Allen's test had a digit DeltaP of 40 mm Hg or more with radial artery compression (false negative). CONCLUSION: Use of the modified Allen's test for screening before radial artery harvest may unnecessarily exclude some patients from use of this conduit and may also place a number of patients at risk for digit ischemia from such harvest. Direct digit pressure measurement is a simple, objective method that may more precisely select patients for radial artery harvest. Additional studies are needed to define objective digital pressure criteria that will accurately predict patients at risk for hand ischemia after radial harvest.

Metabolic adaptation with physical training: 14C-acetate incorporation into tissue lipids.

Forty-eight rats were fed ad libitum, fasted 24 hr, rested 48 hr,and injected i.p. with 40 muCi of 14C-acetate/100 g body weight. Twenty-four rats had followed a progressive physical training program for 12 wk and 24 rats acted as their controls. Following this injection, the rats were sequentially sacrificed at 5-, 10-, 15-, and 20-min intervals and total cholesterol (TC), free cholesterol (FC), and triglyceride (TG) specific activity and concentrations were measured from serum, liver, triceps, and heart tissue. Curves relating specific activity to the time point data were fitted by the method of least squares. Comparison of these curves revealed that serum, liver, and triceps TC and FC specific activity were significantly higher in the trained rats. In contrast, corresponding TC and FC concentrations for these three tissues varied. Liver TC level was significantly less for the trained group, probably due to a reduction in the esterified moiety, since liver FC measures were unchanged. Training resulted in significantly lower TC concentrations in the selected tissues studied even though specific activity curves appeared similar for both groups. Our conclusions are that lipid metabolic adaptation; studied in vivo, occurs in tissues with training, but that these adaptations are not uniform across tissues, lipid moieties, or measurement parameters.

Effect of exercise training on glucose tolerance, in vivo insulin sensitivity, lipid and lipoprotein concentrations in middle-aged men with mild hypertriglyceridemia.

The effects of 9 weeks of aerobic exercise training with maintenance of stable body weight upon insulin sensitivity and upon glucose, lipid, and lipoprotein concentrations were studied in 10 middle-aged men with mild hypertriglyceridemia. Following training, mean maximum oxygen consumption improved from 33.5 +/- 1.9 to 39.3 +/- 1.9 mL/kg/min (means +/- SEM), (P less than 0.01). Glucose concentrations, both fasting and during oral glucose tolerance testing, remained stable but both fasting insulin concentrations and insulin responses to oral glucose decreased (P less than 0.1 and less than 0.01, respectively). In vivo insulin sensitivity improved 25 +/- 6.1% (P less than 0.01) following training. Exercise training resulted in decreases in fasting serum triglyceride concentrations from 203 +/- 12.6 to 126 +/- 9.0 mg/dL (P less than 0.01), primarily as a result of the reduction in VLDL-triglycerides (P less than 0.01). The magnitude in percentage decrease of VLDL-triglycerides was found to be significantly correlated (r = 0.71, P less than 0.05) with the magnitude in percent increase in max VO2. Serum cholesterol levels declined from 211 +/- 8.9 to 193 +/- 11.9 mg/dL (P less than 0.01), and the ratio of HDL-cholesterol to total cholesterol was improved. This study demonstrates that exercise training at a level of intensity feasible for many middle-aged men has beneficial effects on several factors that have been associated with an increased risk of cardiovascular disease.

Papillary mechanics and cardiac morphology of infarcted rat hearts after training.

Infarction of the left ventricle was induced by ligation of the coronary artery in male Sprague-Dawley rats under ketamine-xylazine anesthesia. Three weeks after surgery, animals were assigned to a trained (n = 21; running at 20 m/min, 10% grade, 1 h/day, 5 days/wk) or nontrained group (n = 23) for an additional 8 wk. A third, sham-operated control group (n = 16) remained cage sedentary for 11 wk. Ventricular mass was greater in the trained and nontrained infarct groups [1,335 +/- 57.3 and 1,414 +/- 56.1 mg, respectively (mean +/- SE)] compared with the control group (1,155 +/- 50.9 mg) (P less than or equal to 0.05). The diameter of septal fibers was 13% greater in the trained and 17% greater in the nontrained infarct groups compared with control. The specific peak developed force and maximum rate of force development of left ventricular papillary muscle in vitro were 75 and 62% greater in both infarcted groups compared with the control group; these variables were unaffected by training. Myofibrillar adenosine triphosphatase activity of septum was 20% lower in both infarct groups compared with sham-operated animals. We conclude that exercise training did not alter the magnitude of morphological and physiological adaptations to infarction.

Effects of exercise training on glucose control, lipid metabolism, and insulin sensitivity in hypertriglyceridemia and non-insulin dependent diabetes mellitus.

Exercise training has potential benefits for patients with hyperlipidemia and/or non-insulin dependent diabetes mellitus. In nondiabetic, nonobese subjects with hypertriglyceridemia, exercise training alone increased insulin sensitivity, improved glucose tolerance, and lowered serum triglyceride and cholesterol levels. These improvements did not occur when exercise training alone was given to similar patients with impaired glucose tolerance. In severely obese (X = 125 kg) subjects without diabetes melitus, a 600 calorie diet alone decreased glucose and insulin concentrations and improved glucose tolerance but did not increase insulin sensitivity. The addition of exercise training improved insulin sensitivity. Obese, non-insulin dependent diabetes mellitus subjects on sulfonylurea therapy alone increased insulin levels but failed to improve insulin sensitivity or glucose levels. In contrast, the addition of exercise training to this medication resulted in improved insulin sensitivity and lowered glucose levels. We conclude that exercise training has major effects on lowering triglyceride levels in hyperlipidemic subjects and can potentiate the effect of diet or drug therapy on glucose metabolism in patients with non-insulin dependent diabetes mellitus.

Exercise as a partial therapy for the extremely obese.

The management of the extremely obese patient is best accomplished by a multidisciplinary approach which includes exercise training as an integral component. While diet alone is a potent factor in improving the metabolic complications associated with obesity, the combination of diet and exercise training can further improve these complications and greatly enhance cardiorespiratory function. Although the fitness of extremely obese people is low, individualized exercise programs can be used to safely and progressively train these patients, reduce fatigue, and greatly increase maximum work tolerance. Additional benefits derived from exercise training include improved insulin-mediated glucose utilization, lower serum lipid concentrations, and improved psychological distress scores and anxiety levels. Thus, exercise training can contribute to the success of a weight reducing program by improving metabolic, cardiorespiratory, and psychological factors. Additional important interventions in a multidisciplinary treatment of severe obesity include psychiatric, psychosocial, and vocational counseling.

Sarcoidosis of the pancreas: case report and review of the literature.

Sarcoidosis involving the pancreas is rare. Patients can present with symptoms that mimic pancreatic cancer. We report a case of a male patient with clinical and radiographic findings suggestive of pancreatic cancer as the initial manifestation of sarcoidosis.

Treatment options for perianal Bowen's disease: survery of American Society of Colon and Rectal Surgeons Members.

The aim of this study was to determine current management practices of physicians caring for patients with perianal Bowen's disease. A questionnaire was sent to 1,499 members listed in the 1997 American Society of Colon and Rectal Surgeons Directory asking them how many patients they have treated and which operative or nonoperative treatment option they choose for small (< or =3 cm), large (> 3 cm), and microscopic lesions. Of 1,499, 663 (44.2%) surgeons responded. Not all respondents answered each item. Seventy-five per cent of surgeons surveyed (n = 653) devote greater than 75 per cent of their practice to colon and rectal surgery. Of 642 respondents, 552 (86%) managed a total of <10 patients, and 90/642 (14%), > or =10 patients. Ninety-six per cent of respondents use wide local excision for patients with small lesions. Eighty-seven per cent of respondents use wide local excision for patients with large lesions. Seventy-four per cent treat patients with microscopic disease conservatively and without wide excision. The majority of surgeons caring for patients with perianal Bowen's disease are performing wide local excision for both small and large lesions. Microscopic disease was usually treated conservatively with observation alone.

Upper extremity venous gangrene following coronary artery bypass. A case report and review of the literature.

Acute symptomatic upper extremity deep vein thrombosis (DVT) are estimated to account for only 2-4% of all deep vein thrombosis. Upper extremity DVT leading to phlegmasia cerulea dolens (PCD) occurs in an estimated 2-5% of these cases. Progression of PCD to venous gangrene is extremely rare with only 16 previously reported cases in the literature. Only 7 of the cited cases document significant tissue loss. This report describes a 61-year-old male who developed upper extremity DVT complicated by PCD which led to venous gangrene and limb loss.

Evaluating and prescribing exercise for elderly patients.

Research has demonstrated that exercise training benefits the elderly, just as it does younger age groups. Among benefits reported are improved cardiovascular and respiratory function, reduced coronary artery disease risk, decreased body fat and increased lean body mass, increased bone mass, increased work capacity, greater flexibility, reduced susceptibility to depression, improved self-esteem, and more independence. Before starting a vigorous training program, however, the elderly should undergo a thorough physical examination, including medical history, and an exercise stress test to evaluate cardiovascular status. These test results should be used to indicate intensity, duration, and frequency of exercise, as well as reassure patients of its safety. With this approach, full benefits of regular endurance exercise can be realized.

Compartment syndrome of the arm and disseminated intravascular coagulation.

We present the case of a woman who had coagulopathy and sepsis and who developed compartment syndrome of the arm. We discuss recognition and treatment of arm compartment syndrome and review the literature regarding this condition.

Arthritis and Aerobic Exercise: A Review.

In brief: Despite increasing evidence that regular aerobic exercise yields many benefits for patients with arthritis, patients often are advised to curtail physical activity. Findings from studies of patients with either rheumatoid arthritis or osteoarthritis who participated in an aerobic exercise program show that the subjects made significant gains in aerobic capacity, functional status, muscle strength, and other aspects of performance. In addition, they improved in subjective aspects that might have a positive impact on quality of life, including pain tolerance, joint pain, mood, and social activity. The authors discuss some questions that remain unanswered and present guidelines for physicians who wish to prescribe aerobic exercise for their arthritis patients.

Exercise prescription for chronically ill patients.

Although patients with chronic illnesses typically refrain from exercise, many of them could benefit significantly from mild, long-term exercise therapy. While factors such as pain or weakness often discourage the chronically ill person from being physically active, lack of motivation and lack of knowledge are the primary obstacles. An effective way of overcoming these obstacles is to provide an individualized exercise regimen that both motivates and instructs. Patients who receive an exercise prescription enjoy this individualized approach, tend to exercise safely and quickly become aware of the benefits of exercise therapy as an adjuvant to their medical treatment.

Lightweight remotely actuated switching valve for rebreathing exercise studies.

A new type of switching valve used in rebreathing studies for estimating cardiac output is described. This valve employs a unique deformable elastic element, actuated by low-pressure compressed air, to effect switching. The capability for remote operation (via a compressed air line) and the light weight of the valve (110 g) make the valve especially well suited to exercise stress testing studies. Two valves of this type have been satisfactorily used in graded exercise stress tests in a clinical setting for over 2 yr.

New respiratory gas valve support for graded exercise studies.

We describe a new support structure for respiratory gas valves for use in exercise studies. Use of this structure largely avoids problems of large inertial reactions and feelings of confinement on the part of the subject which have characterized previous systems. The support mechanism consists of a spring-reacted, pivoted boom carried on the end of a counterbalanced swinging beam. This device was designed for use on an adjustable slope motor-driven treadmill, but may be adapted to a variety of other experimental arrangements.